Optimization of spray drying parameters of Amaranthus cruentusjuice using Response Surface Methodology

Abstract

Amaranthus cruentus is a highly perishable leafy vegetable, possessing enormous phytochemicals and nutrients with potential antioxidant, and anti-inflammatory properties. The edible parts of the plant have been reported as a vital source of water soluble betalain compounds alternate to beet roots. Our present study is carried out to determine and evaluate the physicochemical properties of Amaranthus cruentus juice powder with varying concentrations of drying agent (maltodextrin) and inlet temperatures of spray drying. The optimization of juice powder is devised by using Response Surface Methodology (Central Composite Design) which optimizes the drying parameters such as inlet air temperature (IAT) (130–150℃), maltodextrin concentration (MD) (5–10%) and the characterization response are in terms of the Powder Yield, Colour, Water Activity, Betalain Retention (BR), Moisture Content, Bulk Density, TappedDensity, Cohesiveness (HR), Flowability (CI), Water Solubility Index (WSI) and Water Absorption Capacity (WAI). According to Response Surface Methodology, an inlet temperature of 150ºC with 10% maltodextrin concentration was observed as the optimum conditions. The powder yield significantly increases with increasing Maltodextrin concentration while the moisture content decreased. The spinach juice powder could increase the use of spinach juice powder in various nutraceutical applications thus helping in its commercial product formulation.